Nomenclature

Question 1

Define organic chemistry.

Answer 1

Organic chemistry is the chemistry of carbon compounds.

Question 2

Describe the significance of carbon in organic chemistry.

Answer 2

Carbon can form strong covalent bonds with itself, allowing for a vast number of compounds.

Question 3

What is a homologous series?

Answer 3

A homologous series is a group of organic compounds with the same functional group, differing by CH2.

Question 4

List characteristics of a homologous series.

Answer 4

Same functional group, same general formula, similar chemical properties, and gradually changing physical properties.

Question 5

Explain how physical properties change in a homologous series.

Answer 5

As the size of the molecule increases, properties like boiling point and density change.

Question 6

What is the general formula for alkanes?

Answer 6

The general formula for alkanes is CnH2n+2.

Question 7

Differentiate between structural formula and displayed formula.

Answer 7

The structural formula shows how atoms are bonded, while the displayed formula shows all atoms and their bonds.

Question 8

What is a skeletal formula?

Answer 8

A skeletal formula is a simplified displayed formula with all C-H bonds removed.

Question 9

Explain chain isomerism.

Answer 9

Chain isomerism occurs when compounds have the same molecular formula but different longest hydrocarbon chains.

Question 10

Identify the role of functional groups in organic compounds.

Answer 10

Functional groups determine the physical and chemical properties of molecules.

Question 11

What is the relationship between members of a homologous series?

Answer 11

Each member has the same functional group and general formula, with similar chemical properties.

Question 12

Describe the effect of increasing molecule size in a homologous series.

Answer 12

Increasing molecule size affects physical properties like boiling point and density.

Question 13

What does R represent in functional groups?

Answer 13

R represents any other atom or group of atoms, except for hydrogen.

Question 14

Define the term ‘general formula’ in organic chemistry.

Answer 14

A general formula represents a homologous series of compounds using letters and numbers.

Question 15

What is the importance of nomenclature in organic chemistry?

Answer 15

Nomenclature is essential for naming compounds systematically and understanding their structure.

Question 16

Describe the cause of branching in hydrocarbons.

Answer 16

Branching in hydrocarbons is caused by the arrangement of carbon atoms, as seen in examples like pentane and 2,2-dimethylpropane.

Question 17

Define positional isomers and provide an example.

Answer 17

Positional isomers are isomers that differ in the position of a functional group within the molecule. An example is butan-1-ol and butan-2-ol.

Question 18

How do functional group isomers differ from each other?

Answer 18

Functional group isomers have the same molecular formula but different functional groups, resulting in very different chemical properties. For example, butanol and ethoxyethane are functional group isomers.

Question 19

What are stereoisomers and how are they characterized?

Answer 19

Stereoisomers are compounds that have the same atoms connected in the same order but differ in their spatial arrangement.

Question 20

Explain the concept of a chiral carbon.

Answer 20

A chiral carbon is a carbon atom that has four different atoms or groups attached to it, leading to the formation of chiral molecules.

Question 21

What does the term ‘enantiomers’ refer to?

Answer 21

Enantiomers are pairs of optical isomers that are non-superimposable mirror images of each other, similar to left and right hands.

Question 22

How do optical isomers differ in their interaction with plane polarized light?

Answer 22

Optical isomers have identical physical and chemical properties but differ in their ability to rotate plane polarized light.

Question 23

What naming convention is commonly used for enantiomers in biology?

Answer 23

In biology, the d- and l- convention is commonly used to name enantiomers.

Question 24

Provide examples of biological molecules that have enantiomers.

Answer 24

Sugars and amino acids are examples of biological molecules that have enantiomers, with d-isomers of sugars being most common in living organisms and l-isomers of amino acids found in proteins.

Question 25

Describe the significance of enantiomers in drug interactions.

Answer 25

Enantiomers are crucial in drug interactions because they are not superimposable and can fit differently into receptor sites, leading to specific biological effects. Only one enantiomer may have therapeutic properties, while the other may be harmful.

Question 26

How do enantiomers relate to the function of drugs?

Answer 26

The function of drugs often depends on their enantiomers, as only one of the two enantiomers typically binds effectively to the biological receptor, resulting in the desired therapeutic effect.

Question 27

Define enantiomers and their importance in pharmacology.

Answer 27

Enantiomers are pairs of molecules that are mirror images of each other and cannot be superimposed. Their importance in pharmacology lies in the fact that different enantiomers can have vastly different biological activities.

Question 28

Explain the case of thalidomide and its enantiomers.

Answer 28

Thalidomide had two enantiomers: the R enantiomer acted as a sedative and was effective against morning sickness, while the S enantiomer caused severe birth defects by inhibiting blood vessel growth in the fetus.

Question 29

What happened to thalidomide after its initial release?

Answer 29

Thalidomide was withdrawn in 1961 after it was discovered to cause severe limb malformations and other abnormalities in babies, leading to significant disabilities and over half of the affected babies dying.

Question 30

How do the R and S enantiomers of thalidomide differ in their effects?

Answer 30

The R enantiomer of thalidomide is therapeutic and acts as a sedative, while the S enantiomer is harmful and causes birth defects by inhibiting blood vessel growth.

Question 31

Discuss the implications of enantiomer interconversion in the body.

Answer 31

Even if enantiomers are separated before administration, interconversion in the body can occur, making it ineffective to prevent the harmful effects of one enantiomer.

Question 32

What is the role of chiral carbon in enantiomers?

Answer 32

Chiral carbon is a carbon atom that is bonded to four different groups, leading to the formation of enantiomers, which are important in determining the specific interactions of molecules in biological systems.

Question 33

Describe the impact of thalidomide on drug testing regulations.

Answer 33

The tragedy of thalidomide led many countries to tighten their drug testing regimes, resulting in the drug being off the market for many years.

Question 34

How has the understanding of thalidomide’s S form influenced its medical use?

Answer 34

The elucidation of the mode of action of the S form of thalidomide has sparked renewed interest in its use as a treatment for cancer.

Question 35

Define the therapeutic approach of thalidomide in cancer treatment.

Answer 35

Thalidomide may be used to reduce the blood supply to cancerous cells by blocking their ability to build new blood vessels.

Question 36

What precautions are necessary when using thalidomide for cancer treatment?

Answer 36

The use of thalidomide and its derivatives against cancer must be strictly controlled.

Question 37

Explain the significance of thalidomide’s mode of action in cancer therapy.

Answer 37

Understanding the mode of action of thalidomide’s S form is significant as it opens avenues for its application in cancer treatment.